Pharmaceutical composition containing a derivative of orthoaminobenzoic acid as an active ingredient

ABSTRACT

Disclosed is a pharmaceutical composition useful for the treatment of hypertension containing an aminobenzoic acid derivative as an active ingredient represented by the following general formula: ##STR1## wherein  1  R denotes one member selected from the group consisting of the residual groups formed by removing OH at 1(alpha) or 1(beta) position from arabinose, xylose, glucose, galactose, rhamnose and mannose, and  2  R denotes hydrogen or methyl group, or a pharmaceutically acceptable salt thereof.

CROSS-REFERENCES TO RELATED APPLICATION

This application is a continuation-in-part of application, Ser. No. 24092 filed Mar. 26, 1979 now abandoned, and entitled "A MEDICINE CONTAINING A DERIVATIVE OR ORTHOAMINOBENZOIC ACID AS AN ACTIVE INGREDIENT", now abandoned.

BACKGROUND OF THE INVENTION

The present invention relates to a pharmaceutical composition containing an aminobenzoic acid derivative as an active ingredient represented by the following general formula: ##STR2## wherein ¹ R denoted one member selected from the group consisting of the residual groups formed by removing OH at 1 (alpha) or 1 (beta) position from arabinose, xylose, glucose, galactose, rhamnose and mannose, and ² R denotes hydrogen or metyl group, or a pharmaceutically acceptable salt thereof.

The inventors of the present invention, during the course of searching chemical compounds having antitumor activity, have found that chemical compounds represented by the above-mentioned formula (1) have respectively a number of physiological activities such as blood sugar-reducing activity, antihypertensive activity, blood lipid-reducing activity, antiinflammatory activity and central nerve-depressing activity in addition to its antitumor activity.

Although the above-mentioned aminobenzoic acid derivatives are known compounds, no report has been found on the physiological activity of the compounds.

"Inoue, et al. N-Glycosides. XIX. Preparation of anthranilic acid N-glycosides., Chemical Abstracts, Vol. 48 (1954), Column 2001 i." and "Inoue, et al. N-Glycosides. XXV. Paper chromatography of N-glycosides., Chemical Abstracts, Vol. 48 (1954), Column 2003 a." disclose the chemical syntheses of the compounds which are the active ingredients of the pharmaceutical composition of the present invention. However, there is no utility disclosed in this prior arts and no teaching of pharmaceutical "dosage unit forms".

Furthermore, although U.S. Pat. No. 2,659,689 discloses a p-aldimino benzoic ester and a composition for protecting the human skin from erythema producing rays, the composition comprising a solution of p-aldimino benzoic ester, there is no teaching of pharmaceutical "dosage unit forms".

Accordingly, the present invention has the object of providing a pharmaceutical composition having effectiveness in antitumor activity, blood sugar-reducing activity, antihypertensive activity, blood lipid-reducing activity, antiinflammatory activity and central nerve-depressing activity, based on the discovery of the new medical use of the chemical compounds represented by the above-mentioned formula (1).

The present invention will be explained in detail in the following.

BRIEF DESCRIPTION OF THE DRAWING

The annexed FIGS. 1 to 13 show respectively the infrared absorption spectra of respective compound No. 1 to No. 13 in Table 1.

DETAILED DESCRIPTION OF THE INVENTION

The active ingredient of the pharmaceutical composition of the present invention is a compound represented by the following formula: ##STR3## wherein ¹ R and ² R are as described above, or its pharmaceutically acceptable salt selected from the group consisting of its Na-, K-, 1/2Mg-, 1/2Ca- and 1/3Al-salts. The sugar moiety of the active ingredient has a structure of six membered heterocyclic ring.

The method of preparation of the active ingredient of the present invention is illustrated as follows:

A mixture of 4.5 to 5 g of aminobenzoic acid, 5-6 g of mono saccharide (L-arabinose, D-xylose, D-glucose, D-galactose, L-rhamnose or D-mannose) and 0.1 to 0.5 g of ammonium chloride (formic acid, hydrochloric acid, acetic acid, or magnesium chloride) was heated in 40 to 90 ml of 95 to 100% ethanol or pure methanol under a reflux condenser to induce condensation. After the reaction is over, the reactant is left at room temperature or in a cool place and the crystals separated out are collected by filtering the reactant solution. These crystals are washed with water, ethanol or ethyl ether, and then recrystallized from methanol, ethanol or an aqueous solution of methanol or ethanol.

In order to substitute the hydrogen atom of the carboxyl group of the thus prepared compound with a base, it is preferable to follow the known method. The compound, ortho-aminobenzoic acid -N- pyranoside, is dissolved in an aqueous ethanolic solution and an inorganic salt is added to the solution to effect the substitution.

The physical properties of the compounds (the active ingredient of the pharmaceutical composition of the present invention) prepared by the above-mentioned methods are shown in Table 1, and their infrared absorption spectra are respectively shown in FIGS. 1 to 13. Methods of determination of the physical properties are as follows.

                                      TABLE 1                                      __________________________________________________________________________     Physical Properties of the Active Ingredients                                                                 Specific                                                                              Elementary                                                                            Ultraviolet                                             Melting point                                                                           rotation                                                                              analysis (%)                                                                          absorption Maximum                Compound               (°C.)                                                                           |α|.sub.D.sup.20                                              C:H:N  (millimicron)                     __________________________________________________________________________       o-Aminobenzoic acid-N-L-arabinoside                                                                167      -11 (10° C.)                                                                    50.1:6.0:5.1                                                                         330, 250, 220                                                    in ethanol                                                                            (50.2:6.0:4.9)*                            Sodium o-aminobenzoate-N-L-arabinoside                                                             155-162(decomp.)                                                                        -44     46.6:5.1:4.6                                                                         315, 246, 212                                                    in water                                                                              (46.6:5.2:4.5)                             o-Aminobenzoic acid-N-D-xyloside                                                                   168(decomp.)                                                                            +11 (18° C.)                                                                    53.4:5.7:5.0                                                                         330, 250, 220                                                    in ethanol                                                                            (53.5:5.6:5.2)                             Sodium o-aminobenzoate-N-xyloside                                                                  160-170(decomp.)                                                                        +1      49.7:4.8:4.7                                                                         316, 248, 215                                                    in water                                                                              (49.5:4.8:4.8)                             o-Aminobenzoic acid-N-D-glucoside                                                                  137-138(decomp.)                                                                        +68 (15° C.)                                                                    49.0:6.1:4.2                                                                         330, 250, 220                                                    in ethanol                                                                            (49.2:6.0:4.4)                             Sodium o-aminobenzoate-N-D-glucoside                                                               145-160  +6      46.1:5.2:4.0                                                                         318, 249, 215                                                    in water                                                                              (46.0:5.3:4.1)                             o-Aminobenzoic acid-N-D-galactoside                                                                152      -16     52.3:6.0:4.8                                                                         330, 250, 220                                                    in ethanol                                                                            (52.2:5.7:4.7)                             Sodium o-aminobenzoate-N-D-galactoside                                                             157-163(decomp.)                                                                        -9      48.5:5.2:4.4                                                                         317, 248, 215                                                    in water                                                                              (48.6:5.0:4.4)                             o-Aminobenzoic acid-N-L-rhamnoside                                                                 165-166(decomp.)                                                                        +52     54.8:5.9:4.9                                                                         330, 250, 219                                                    in ethanol                                                                            (55.1:6.0:4.9)                           10.                                                                              Sodium o-aminobenzoate-N-L-rhamnoside                                                              152-162(decomp.)                                                                        +54     51.0:5.4:4.9                                                                         320, 249, 215                                                    in water                                                                              (51.1:5.2:4.6)                             o-Aminobenzoic acid-N-D-mannoside                                                                  150-165(decomp.)                                                                        -10     51.9:5.8:4.7                                                                         333, 249, 218                                                    in ethanol                                                                            (52.2:5.7:4.7)                             Sodium o-aminobenzoate-N-D-mannoside                                                               148-167(decomp.)                                                                        -2      46.1:5.5:4.0                                                                         330, 250, 219                                                    in water                                                                              (46.0:5.3:4.1)                             Methyl o-aminobenzoate-N-D-mannoside                                                               177-178  -54     49.1:6.1:4.3                                                                         330, 251,                                                        in ethanol                                                                            (48.1:6.6:4.0)                           __________________________________________________________________________      Note:                                                                          (: : ): theoretical values of C, H and N (%).                            

(1) Melting point: determined by the use of micro melting point determination apparatus made by Yanagimoto Works, Japan.

(2) Specific rotation: determined by using direct-reading polarimeter Model OR-50 made by Yanagimoto Works, Japan, with a thickness of 50 mm of an aqueous ethanolic solution of the acidic active ingredient and an aqueous solution of the sodium salt of the acidic active ingredient.

(3) Molecular composition: Elementary analysis was carried out by using CHN-Coder Model MT-2 made by Yanagimoto Works, Japan.

(4) Ultraviolet absorption spectrum: by using self-recording spectrophotometer Model PS-3T made by Hitachi Works, Japan, on an aqueous ethanolic solution of the acidic active ingredient and on an aqueous solution of the sodium salt of the acidic active ingredient of the medicine.

(5) Infrared absorption spectrum: determined by KBr-method using infrated absorption spectrometer Model DS-701G made by Nippon Bunko Co. Ltd. Japan. The chart number of the spectrogram coincides with the number of specimens of the active ingredient of the pharmaceutical composition.

The following are the physiological properties of the active ingredient of pharmaceutical compositions of the present invention described in the order of (1) acute toxicity, (2) antimicrobial activity, (3) mutagenicity, (4) delayed-type intracutaneous reaction and (5) antibody-producing activity.

(1) Acute toxicity:

Acute toxicity of the active ingredient was examined by respective intraperitoneal and oral (forcible) administration to ICR-JCL mice. The specimen was dissolved in the physiological saline solution in intraperitoneal administration, and dissolved in distilled water in oral administration.

Their symptoms were observed after administration until the 7th day of administration, and LD₅₀ of the specimen was obtained from the mortality accumulated to the 7th day, according to the graphic method of Litchfield-Wilcoxon. The results are shown in Table 2. As is seen in Table 2, more than half of the active ingredients are qualified to be highly safe active ingredients of the medicine.

                  TABLE 2                                                          ______________________________________                                         Acute toxicity of the active ingredients                                       (LD.sub.50 in g/kg)                                                                                Route                                                                          of administration                                                                intra-                                                   Compound              peritoneal                                                                               oral                                           ______________________________________                                         Sodium o-aminobenzoate-N-L-arabinoside                                                               7.48      6.35                                           Sodium o-aminobenzoate-N-D-xyloside                                                                  9.27      6.35                                           Sodium o-aminobenzoate-N-D-glucoside                                                                 13.38     8.96                                           Sodium o-aminobenzoate-N-D-galactoside                                                               7.42      6.10                                           Sodium o-aminobenzoate-N-L-rhamnoside                                                                >15.00    12.50                                          Sodium o-aminobenzoate-N-D-mannoside                                                                 >10.00    >10.00                                         Methyl o-aminobenzoate-N-D-mannoside                                                                 2.5       >7.50                                          ______________________________________                                    

(2) Anti microbial activity:

The active ingredient was dissolved in distilled water at a series of two fold dilution system. These diluted solutions were mixed with agar medium in 9 times by volume and the mixture was poured into a petridish. Heartinfusion agar medium was used for bacteria, and Sabouraud's agar medium was used for fungi. After streaking with the pre-culture, the inoculated plates were incubated at 37° C. for 20 to 24 hours for bacteria and at 25° C. for 3 to 7 days for fungi, and then the growth was examined. The following microorganisms were used for assessing the antimicrobial activity:

Pseudomonas aeruginosa IAM 1514

Escherchia coli IFO 12734

Staphylococcus aureus 209 P

Bacillus subtilis IAM 1069

Saccharomyces cerevisiae IAM 4207

Candida albicans ATCC 752

Trichophyton mentagrophytes IFO 6124

Aspergillus niger IAM 3001

As the result of the above-mentioned tests, it was found that none of the tested active ingredients showed growth inhibition of the microorganisms at a concentration of 1 mg/ml.

(3) Mutagenicity:

As the first stage, the active ingredients were tested by rec-assay (i), and as the second stage, they were tested by reversion assay (ii).

(i) A strain of Bacillus subtilis M 45, a defectant of recombination repair, and a wild strain of Bacillus subtilis H 17 keeping recombination repair activity were inoculated to make their own streaks not crossed at the start on a B-2 agar culture plate (made by dissolving 10 g of meat extract, 10 g of polypeptone, 5 g of sodium chloride and 15 g of agar in 1000 ml of distilled water at a pH of 7.0). Then, a circular sheet of filter paper 8 mm in diameter, which absorbed 0.04 ml of an aqueous solution of the active ingredient (using sterilized water) was put on the surface of the agar plate so as to cover the starting point of the above-mentioned streaks of bacterial culture. The inoculated B-2 agar culture was kept at 37° C. for a night and the length of growth-inhibited region was measured. Kanamycin was used as the negative control and Mitomycin C was used as the positive control. The results of the rec-assay are shown in Table 3.

(ii) The strains TA 98 and TA 100 (both are histidine requiring) of Salmonella typhimurium were used in the reversion assay.

Into 2 ml of a soft agar culture medium (the medium itself contains 6 g of sodium chloride and 6 g of agar in 1000 ml of distilled water) to which one tenth by volume of an aqueous solution of 0.5 mM of biotin and 0.5 mM of histidine had been added, 0.1 ml of the bacterial suspension and 0.1 ml of an aqueous solution of the active ingredient were admixed and the mixture was layered on the minimum agar culture medium. After 2 days of incubation at 37° C., the number of revertant colonies was counted. Furylfuramide (AF-2) was used as the positive control. The results of the reversion assay are shown in Table 4.

As is seen in Table 3, the active ingredients showed a weak mutagenicity only at a high concentration of 5000 microgram/disk. And as is seen in Table 4, the rate of occurrence of mutation by the active ingredient of the pharmaceutical composition of the present invention did not shown any difference from that in the control to which no substance was added, even at a high concentration of 5000 microgram/plate. These findings demonstrate that the active ingredient is safe from the standpoint of mutagenicity.

                  TABLE 3                                                          ______________________________________                                         Result of rec-assay                                                                               Length of growth-                                                              inhibition zone                                                             Concen-                *differ-                                                tration  M 45    H 17  ence                                    Compound        (μg/disk)                                                                            (mm)    (mm)  (mm)                                    ______________________________________                                         Sodium o-aminobenzoate-N-                                                                      500      0       0     0                                       L-arabinoside   5,000    8       4     4                                       Sodium o-aminobenzoate-N-                                                                      500      0       0     0                                       D-xyloside      5,000    7       3     4                                       Sodium o-aminobenzoate-N-                                                                      500      0       0     0                                       D-glucoside     5,000    5       2     3                                       Sodium o-aminobenzoate-N-                                                                      500      0       0     0                                       D-galactoside   5,000    6       1     5                                       Sodium o-aminobenzoate-N-                                                                      500      0       0     0                                       L-rhamnoside    5,000    6       2     4                                       Sodium o-aminobenzoate-N-                                                                      500      0       0     0                                       D-mannoside     5,000    7       1     6                                       Methyl o-aminobenzoate-N-                                                                      500      0       0     0                                       D-mannoside     5,000    7       3     4                                       Kanamycin       10       5       4     1                                       Mitomycin C     0.05     12      2     10                                      ______________________________________                                          Note:                                                                          *difference = length of inhibition zone of M 45 minus length of inhibitio      zone of H 17.                                                            

                  TABLE 4                                                          ______________________________________                                         Results of Reversion assay                                                                          Number of revertant                                                     Concen-                                                                               colonies                                                                  tration  (n/plate)                                             Compound        (μg/plate)                                                                           TA 100     TA 98                                      ______________________________________                                         Sodium o-aminobenzoate-N-                                                                      5,000    59         4                                          L-arabinoside                                                                  Sodium o-aminobenzoate-N-                                                                      5,000    166        4                                          D-xyloside                                                                     Sodium o-aminobenzoate-N-                                                                      5,000    151        5                                          D-glucoside                                                                    Sodium o-aminobenzoate-N-                                                                      5,000    151        6                                          D-galactoside                                                                  Sodium o-aminobenzoate-N-                                                                      5,000    61         9                                          L-rhamnoside                                                                   Sodium o-aminobenzoate-N-                                                                      5,000    91         7                                          D-mannoside                                                                    Methyl o-aminobenzoate-N-                                                                      5,000    95         8                                          D-mannoside                                                                    Furyluramide    0.1      911        167                                        Control (nothing added)                                                                        --       149        13                                         ______________________________________                                    

(4) Delayed-type intracutaneous reaction

In order to know the effects of the active ingredients on cellular immunity, the foot pad reaction test was carried out using ICR-JCL mice as experimental animals and erythrocytes of sheep as an antigen.

A mouse was primary-sensitized by injecting 0.2 ml of 10% suspension of sheep erythrocytes in physiological saline solution from the caudal vein and after 7 days of the first sensitization, 0.05 ml of 40% suspension of sheep erythrocytes in physiological saline solution was injected in the foot pad for the second sensitization. The thickness of the foot pad was determined on the next day. The administration of the active ingredient of the pharmaceutical composition of the present invention was carried out at the dosage of 250 mg/kg/day once a day for consecutive 5 days centering around the day when the first sensitization was carried out.

As the result, the increment of the thickness of the foot pad of the mouse administered with the active ingredient showed no significant difference as compared to the increment in the group of mouse not administered with the active ingredient.

(5) Antibody-producing activity

In order to know the effects of the active ingredients on humoral immunity, the hemagglutination test was carried out using ICR-JCL mice sensitized with sheep erythrocytes.

A mouse was sensitized by injecting 0.2 ml of 10% suspension of sheep erythrocytes in physiological saline solution from the caudal vein and after 7 days of sensitization the mouse blood was sampled for the hemagglutination test of determination of the antibody-producing activity. The active ingredient was administered for consecutive 5 days centering around the day of sensitization, intraperitoneally at the dosage of 250 mg/kg/day.

As the result, there was no significant difference in agglutination titer between the group administered with the active ingredient and the control group.

The following are the pharmacological properties of the active ingredients of the pharmaceutical composition of the present invention described in the order of (1) blood sugar-reducing activity, (2) antihypertensive activity, (3) antitumour activity, (4) analgetic activity, (5) antipyretic activity, (6) antiinflammatory activity, and (7) blood lipid reducing activity.

(1) Blood sugar reducing activity

Streptozotocin was administered intraperitoneally to a group of Wistar rats at a dosage of 60 mg/kg and after confirming the positivity of urinary sugar of the animals on the 8th day, regular insulin was further administered to the rats to reduce both the uninary sugar and the blood sugar. Out of thus treated animals, those which certainly showed a higher urinary sugar value and also a higher blood sugar value after a few days of insulin-administration were used as the model animals suffering from artificial diabetes mellitus. The active ingredient was administered to the model animals orally as a solution in distilled water at the respective dosages of 30 and 300 mg/kg. Blood specimens were collected after 3 and 6 hours of the administration, and the determination of glucose in the specimen was carried out by using a RaBA-kit (made by Chugai Pharmaceutical Co., Japan) according to the enzyme method.

The results are shown in Table 5. As is seen in Table 5, the difference between the values of blood sugar before and after the administration of every active ingredient (Δ value) was larger than the Δ value of control.

Especially, the activity of reducing blood sugar was conspicuous in the case of sodium o-aminobenzoate-N-L-arabinoside, sodium o-aminobenzoate-N-D-glucoside, sodium o-aminobenzoate-N-L-rhamnoside, and sodium o-aminobenzoate-N-D-mannoside, the Δ value of these compounds being 150 to 460 mg/dl at the dosage of as low as 30 mg/kg.

                  TABLE 5                                                          ______________________________________                                         Blood sugar-reducing activity                                                                          Change Δ                                                                 value mg/dl                                                                    of blood sugar                                                         Dose    after                                                  Compound          (mg/kg)   3 hr     6 hr                                      ______________________________________                                         Sodium o-aminobenzoate-N-L-                                                                      30        -254     -225                                      arabinoside       300       -108     -83                                       Sodium o-aminobenzoate-N-D-                                                                      30        -62      -60                                       xyloside          300       -80      -76                                       Sodium o-aminobenzoate-N-D-                                                                      30        -220     -200                                      glucoside         300       -134     -217                                      Sodium o-aminobenzoate-N-D-                                                                      30        -82      -42                                       galactoside       300       -95      -49                                       Sodium o-aminobenzoate-N-L-                                                                      30        -156     -124                                      rhamnoside        300       -462     -397                                      Sodium o-aminobenzoate-N-D-                                                                      30        -180     -110                                      mannoside         300       -230     -150                                      Methyl o-aminobenzoate-N-D-                                                                      30        -121     -86                                       mannoside         300       -166     -147                                      Control           --        -36      -39                                       ______________________________________                                    

(2) Antihypertensive activity

An aqueous solution of the active ingredient in distilled water was orally administered to rats of spontaneous hypertension at respective dosages of 30 and 300 mg/kg and their blood pressure was determined after 3 and 6 hours of administration by a sphygmomanometer (made by Ueda Works, Japan, Model USM-105R). The difference of blood pressures before and after the administration was used to evaluate the antihypertensive activity of the active ingredients. Mean value of blood pressure of the above-mentioned rats in spontaneous hypertension was 200 mmHg.

The results are shown in Table 6. As is seen in Table 6, all the tested active ingredients clearly showed that antihypertensive effect.

                  TABLE 6                                                          ______________________________________                                         Antihypertensive activity                                                                             Reduced                                                                        amount of                                                                      blood pressure                                                                 after                                                                   Dose rate                                                                               3 hr     6 hr                                         Compound          (mg/kg)    (mm Hg)                                           ______________________________________                                         Sodium o-aminobenzoate-N-L-                                                                      30         13       9                                        arabinoside       300        22       25                                       Sodium o-aminobenzoate-N-D-                                                                      30         16       16                                       xyloside          300        9        5                                        Sodium o-aminobenzoate-N-D-                                                                      30         8        5                                        glucoside         300        26       20                                       Sodium o-aminobenzoate-N-D-                                                                      30         9        16                                       galactoside       300        9        8                                        Sodium o-aminobenzoate-N-L-                                                                      30         13       19                                       rhamnoside        300        28       20                                       Sodium o-aminobenzoate-N-D-                                                                      30         12       14                                       mannoside         300        24       22                                       Methyl o-aminobenzoate-N-D-                                                                      30         18       14                                       mannoside         300        26       21                                       Control           --         -2*      2                                        ______________________________________                                          Note:                                                                          *Blood pressure raised by 2mmHg.                                         

(3) Antitumour activity

Sarcoma 180 were transplanted subcutaneously into the right axillary of ICR-JCL mice at the rate of 1×10⁶ cells/mouse, and from after 24 hours of transplantation an aqueous solution of the active ingredient in sterilized physiological saline solution was orally administered every other day at a dose rate of 500 mg/kg, 10 times in all. On the 25th day of the transplantation, the nodular tumour(s) was extirpated and weighed.

The inhibition ratio (I.R.) (%) of the active ingredient was calculated by the following formula:

    (1-T/C)×100=I.R.(%)

wherein T: mean weight of the tumour(s) in treated group of mice

C: mean weight of the tumour(s) in control group* of mice

The results of the test are shown in Table 7. As is seen in Table 7, all the active ingredients tested exhibited an antitumour activity.

                  TABLE 7                                                          ______________________________________                                         Antitumour activity against Sarcoma - 180                                                               Inhibition                                            Compound                 ratio (I.R. %)                                        ______________________________________                                         Sodium o-aminobenzoate-N-L-arabinoside                                                                  44.4                                                  Sodium o-aminobenzoate-N-D-xyloside                                                                     18.9                                                  Sodium o-aminobenzoate-N-D-glucoside                                                                    22.4                                                  Sodium o-aminobenzoate-N-D-galactoside                                                                  21.6                                                  Sodium o-aminobenzoate-N-L-rhamnoside                                                                   57.4                                                  Sodium o-aminobenzoate-N-D-mannoside                                                                    32.0                                                  Methyl o-aminobenzoate-N-D-mannoside                                                                    59.0                                                  ______________________________________                                          Note:                                                                          Amount of administration was 10 × 500mg/kg p.o.                    

(4) Analgetic activity

DETERMINATION BY THE MECHANICAL STIMULATION METHOD (BY APPLYING PRESSURE)

Female ICR mice which showed a threshold value of pain of 50 to 80 mmHg when their tail base part was pressured by a pressure stimulation apparatus (made by Natsume Works, Japan) of Takagi and Kameyama were chosen as test animals, ten animals comprising a group.

After administering the active ingredient, the test was carried out as the time passes and the applied pressure and the time period until the animal showed a quasi-escaping reaction were determined to evaluate the analgetic activity of the active ingredient.

The results are shown in Table 8. As is seen in Table 8, the pressure applied on animals when the animal showed the quasi-escaping reaction was higher in animals to which the active ingredient had been applied than in animals not administered, and the time period from the beginning to the time point when the animal showed the reaction was longer in animals administered with the active ingredient than in animals not administered. Thus, the analgetic activity of the active ingredient was confirmed.

DETERMINATION BY THE CHEMICAL STIMULATION METHOD

The active ingredient was orally administered to a group (ten animals) of female ICR mice of age of 5 to 6 weeks, and after 30 min of the administration an aqueous 0.6% acetic acid solution was intraperitoneally injected into the mouse at a dose rate of 0.1 ml/10 g of body weight. The number of writhing motion which occurred in the mouse during 10 minutes after 10 minutes of intraperitoneal administration was recorded. The analgetic activity was evaluated from the writhing syndrome inhibiting ratio obtained by the following formula:

    (1-T/C)×100=writhing syndrome-inhibiting ratio(%),

wherein T: mean number of writhing syndrome in the group administered

C: mean number of writhing syndrome in the control group.

The results are shown in Table 9. As is seen in Table 9, every active ingredient of the pharmaceutical composition of the present invention showed analgetic activity. The above-mentioned process was carried out following the method of Kostet et al. (1959)

                  TABLE 8                                                          ______________________________________                                         Analgetic activity by the mechanical stimulation                               method                                                                                          Quasi-escape reaction                                                          pressure at                                                                            time until                                                             (mm Hg) (sec)                                                 Compound           occurrence                                                  ______________________________________                                         Sodium o-aminobenzoate-N-L-                                                                       82        38                                                arabinoside                                                                    Sodium o-aminobenzoate-N-D-                                                                       88        37                                                xyloside                                                                       Sodium o-aminobenzoate-N-D-                                                                       88        36                                                glucoside                                                                      Sodium o-aminobenzoate-N-D-                                                                       80        36                                                galactoside                                                                    Sodium o-aminobenzoate-N-L-                                                                       79        40                                                rhamnoside                                                                     Sodium o-aminobenzoate-N-D-                                                                       92        41                                                mannoside                                                                      Methyl o-aminobenzoate-N-D-                                                                       75        35                                                mannoside                                                                      Control            70        33                                                ______________________________________                                          Note:                                                                          Amount of administration, 1000 mg/kg p.o.                                

                  TABLE 9                                                          ______________________________________                                         Analgetic activity by the chemical stimulation method                          Compound                I.R. (%)                                               ______________________________________                                         Sodium o-aminobenzoate-N-L-arabinoside                                                                 43.1                                                   Sodium o-aminobenzoate-N-D-xyloside                                                                    27.9                                                   Sodium o-aminobenzoate-N-D-glucoside                                                                   24.5                                                   Sodium o-aminobenzoate-N-D-galactoside                                                                 19.8                                                   Sodium o-aminobenzoate-N-L-rhamnoside                                                                  52.1                                                   Sodium o-aminobenzoate-N-D-mannoside                                                                   43.4                                                   Methyl o-aminobenzoate-N-D-mannoside                                                                   40.5                                                   ______________________________________                                          Note:-                                                                         Amount of administration was 1000mg/kg p.o.                              

(5) Antipyretic activity

Following the method of Winter et al. (1961), a 20% suspension of beer yeast was subcutaneously injected to a group (consisting of 6 animals) of rats, and after 10 hours of fasting, the active ingredient was orally administered to the rats and their rectal temperature was determined.

The antipyretic activity is expressed by the ratio of inhibiting pyrexia due to beer yeast (I.R.%) at the time when the antipyretic activity of the active ingredient is at its maximum according to the following formula:

    Antipyretic activity=I.R.(%)=(C.sub.1 -T)/(C.sub.1 -C.sub.2)×100

wherein T: mean rectal temperature of rats to which the active ingredient was administered.

C₁ : mean rectal temperature of rats injected beer yeast, without the active ingredient.

C₂ : mean rectal temperature of untreated rats (control)

The results are shown in Table 10. As is seen in Table 10, all the active ingredients exhibited a considerable antipyretic activity.

                  TABLE 10                                                         ______________________________________                                         Antipyretic activity                                                                                 Antipyretic activity                                                           (suppressing pyrexia)                                    Compound              I.R. (%)                                                 ______________________________________                                         Sodium o-aminobenzoate-N-L-arabinoside                                                               35.7                                                     Sodium o-aminobenzoate-N-D-xyloside                                                                  29.8                                                     Sodium o-aminobenzoate-N-D-glucoside                                                                 15.6                                                     Sodium o-aminobenzoate-N-D-galactoside                                                               40.6                                                     Sodium o-aminobenzoate-N-L-rhamnoside                                                                66.6                                                     Sodium o-aminobenzoate-N-D-mannoside                                                                 19.8                                                     Methyl o-aminobenzoate-N-D-mannoside                                                                 25.0                                                     ______________________________________                                    

(6) Antiinflammatory activity

(a) Carrageenin-edema inhibitory activity

Following the method of Van Arman et al. (1963), the active ingredient was forcibly and orally administered to each rat of a group consisting of 10 animals at the dose rate of 1000 mg/kg, and after one hour of the administration 0.1 ml of 1% suspension of carrageenin in physiological saline solution was injected to their right foot pad. The volume of the foot pad was determined as time passes and the antiinflammatory activity was expressed by the ratio of inhibition of the swelling of the foot pad due to carrageenin by the active ingredient, using the determined value of 1-4 hours from the injection and calculating by the following formula:

    (1-T/C)×100=I.R.(%)=antiinflammatory activity

wherein T: Mean value of volumes of planta in administered animals

C: Mean value of volume of the foot pad of control (not administered and then injected)

The results are shown in Table 11. As is seen in Table 11, all the ingredients tested showed the inhibitory activity against the edema caused by carrageenin.

(b) Antigranuloma activity

Following the method of Winter et al. (1963), two cotton wool pellets were implanted into the skin of back of each rat of a group consisting of 6 rats at the symmetrical positions having the median line as the axis of symmetry, the weight of one pellet being 30±1 mg. Oral administration of 1000 mg/kg/day of the active ingredient was carried out for consecutive 7 days. On the 8th day, the granuloma formed in the rats was extirpated and weighed after drying. The antigranuloma activity expressed by the ratio of inhibition of the growth of the granuloma (I.R.,%) was calculated in a manner as shown in (6) (a), and the results are shown in Table 11. As is seen in Table 11, each active ingredient exhibited the inhibiting activity of growth of the granuloma.

(c) Antiexudation activity

Following the method of Baris et al. (1965), a volume of air was injected subcutaneously in the back of each rat of a group consisting of 6 rats to make a air pouch, and then 0.5 ml of 1% croton oil solution in sesame oil was injected into the pouch. The oral administration of 1000 mg/kg/day of the active ingredient was then began to continue for 5 days. On the 6th day, the amount of exudated liquid into the pouch was determined and the antiexudation activity expressed by the ratio of inhibitory activity to exudation was calculated in a manner as shown in (6) (a). The results are shown in Table 11. As is seen in Table 11, all the active ingredient tested exhibited the antiexudation activity.

(d) Antiadjuvant arthritis activity

Following the method of Fujiware et al. (1971), Mycobacterium tuberculosis suspended in liquid paraffin was injected subcutaneously into the right foot pad of each rat of group consisting of 6 rats. After 14 days of the injection, rats with similar volume of the foot pad were chosen to form groups (10 animals/group), each active ingredient was orally administered daily from the 15th day for consecutive 7 days. The volume of the foot pad of rats was determined, and the antiadjuvant arthritis activity of each active ingredient was calculated as the ratio of inhibiting the swelling of the foot pad by using the formula shown in (6) (a). The results are shown in Table 11. As is seen in Table 11, all the tested active ingredient exhibited the antiadjuvant arthritis activity.

                  TABLE 11                                                         ______________________________________                                         Antiinflammatory activity                                                      expressed                                                                                             *granu-  *exuda-                                        Compound       *edema  loma     tion  *arthritis                               ______________________________________                                         Sodium o-aminobenzoate-                                                                       26.0    6.3      10.5  22.7                                     N-L-arabinoside                                                                Sodium o-aminobenzoate-                                                                       4.6     10.1     18.0  19.0                                     N-L-rhamnoside                                                                 Sodium o-aminobenzoate-                                                                       6.9     4.7      12.9  16.1                                     N-D-galactoside                                                                Sodium o-aminobenzoate-                                                                       20.1    12.6     17.8  28.6                                     N-D-xyloside                                                                   Sodium o-aminobenzoate-                                                                       4.0     7.9      9.1   12.1                                     N-D-glucoside                                                                  Sodium o-aminobenzoate-                                                                       4.8     11.8     7.1   17.8                                     N-D-mannoside                                                                  Methyl o-aminobenzoate-                                                                       21.5    10.7     15.4  11.5                                     N-D-mannoside                                                                  ______________________________________                                          Note:-                                                                         Amount of administration of the active ingredient = 1000 mg/kg           

(7) Blood lipid reducing activity

Japanese male white rabbits were fed for about 3 months with solid feed (CR-1) containing 1% of cholesterol and those animals in which the increase of seral lipid component was confirmed were used as the model animals having experimental arteriosclerosis.

An aqueous solution of the active ingredient in distilled water was administered respectively at the dose rates of 30 and 300 mg/kg orally and after the administration, blood specimen was collected as time passes from the auricular vein and the change of total cholesterol (determined by the enzyme method), phospholipid (determined by the enzyme method) and beta-lipoprotein (determined by turbidmetry) in the serum was observed.

The results are shown in Table 12. In Table 12, the values of serum cholesterol (mean value of 550 mg/dl), of phospholipid (mean value of 320 mg/dl) and of beta-lipoprotein (mean value of 2500 mg/kg) before administration were respectively subtracted from the respective values after 3 and 6 hours of the administration, and only the differences are shown, respectively. Therefore, the minus value shows the decrease and the plus value shows the increase of the respective values due to the administration. As is clearly seen in Table 12, generally, the active ingredients exhibited the activity of reducing the lipid components as compared to control.

                                      TABLE 12                                     __________________________________________________________________________     Activity of reducing blood lipids                                                                       Phospholipid                                                                          beta-Lipoprotein                                                                        Cholesterol                                               Dose (mg/dl)                                                                               (mg/dl)  (mg/dl)                               Compound            (mg/kg)                                                                             3 hr                                                                               6 hr                                                                              3 hr 6 hr                                                                               3 hr                                                                               6 hr                              __________________________________________________________________________     Sodium o-aminobenzoate-N-D-mannoside                                                               30   -40 -40                                                                               -132 -175                                                                               -98 -74                                                   300  -43 -59                                                                               -174 -158                                                                               -120                                                                               -135                              Sodium o-aminobenzoate-N-D-glucoside                                                               30   -27 -40                                                                               -142 -169                                                                               -96 -77                                                   300  -33 -43                                                                               -200 -203                                                                               -72 -105                              Sodium o-aminobenzoate-N-D-galactoside                                                             30   +11 -27                                                                               -192 -113                                                                               +3  -25                                                   300    0 -30                                                                               -380 -194                                                                               +10 -75                               Sodium o-aminobenzoate-N-L-arabinoside                                                             30   -26 -51                                                                               -213 -179                                                                               +3  -100                                                  300  -74 -87                                                                               -300 -202                                                                               -5  -210                              Sodium o-aminobenzoate-N-L-rhamnoside                                                              30   -23 -23                                                                               -148 -197                                                                               -122                                                                               -115                                                  300  -25 -19                                                                               -220 -284                                                                               -180                                                                               -175                              Sodium o-aminobenzoate-N-D-xyloside                                                                30   -19 -47                                                                               -179 -181                                                                               -50 -60                                                   300  -23 -64                                                                               -244 -320                                                                               -100                                                                               -125                              Methyl o-aminobenzoate-N-D-mannoside                                                               30   -24 -32                                                                               -144 -127                                                                               -181                                                                               -163                                                  300  -37 -39                                                                               -201 -139                                                                               -230                                                                               -215                              Control                    0 -19                                                                                 0  +3  +8  -4                                __________________________________________________________________________

The formulation of the active ingredients to make the pharmaceutical composition of the present invention is described below.

In the case where the pharmaceutical composition is used as an antiinflammatory agent, it is possible to use the pharmaceutical composition in the form which is convenient to produce the effectiveness according to the kinds and the symptoms of the disease, and moreover, the active ingredient may be used by itself or may be used as mixtures combined with any diluent allowable in pharmaceutical process and with other medicines.

The pharmaceutical composition of the present invention is administered orally or parenterally and accordingly, the pharmaceutical composition of the present invention may take any form optionally for the oral or parental administration.

The pharmaceutical composition of the present invention may be offered as a form of unit administration. The form of the pharmaceutical composition of the present invention may be powder, granule, tablet, sugar-coated tablet, capsulated one, suppository, suspension, solution, emulsifiable concentrate, ampouled one, injection, etc. As a diluent, any one of solids, liquids and semisolids may be utilized, for instance, excipients, fillers, binders, wetting agents, disintegrating agents, surfactants, demulcents, dispersing agents, buffering agents, perfumes, preserratives, dissolution aids and solvents. Moreover, one or more than one of these adjuvants may be used in combination or in mixtures.

The pharmaceutical composition of the present invention may be formulated by any known method, and the amount of the active ingredient contained in the composition (preparation) is generally from 0.01% to 100% by weight.

The pharmaceutical composition of the present invention may be administered orally or parenterally to human or animals, however, it is preferably administered orally. Sublingual administration is included in oral administration. Parenteral administration includes subcutaneous-, intramuscular- and intravenous injection and the injection by drop method.

The dose of the pharmaceutical composition of the present invention depends upon the age, the personal difference and the state of disease, and whether the object is human or animal and accordingly, an extraordinary amount may be administered other than the following dose: Generally, for human, the oral dose is 0.1-1000 mg/kg body weight/day, preferably 1-500 mg/kg/day and the parenteral dose is 0.01-200 mg/kg/day, preferably 0.1-100 mg/kg/day divided into 1-4 parts, one part being administered in one time.

The followings are the more detailed explanation of the formulation and the production of the pharmaceutical composition of the present invention in examples.

EXAMPLE 1 (FORMULATION)

10 parts by weight of one of the active ingredients of the present invention (Sodium o-aminobenzoate-N-L-arabinoside),

15 parts by weight of (heavy) magnesium oxide and

75 parts by weight of lactose were uniformly mixed and formulated into powder or granules. The powder is filled is capsules to be capsulated formulation.

EXAMPLE 2 (FORMULATION)

45 parts by weight of one of the active ingredients of the present invention (Sodium o-aminobenzoate-N-D-xyloside),

15 parts by weight of starch,

16 parts by weight of lacotse,

21 parts by weight of crystalline cellulose,

3 parts by weight of polyvinyl alcohol and

30 parts by weight of water were uniformely mixed, crushed and formulated, and then dried and shifted to be granules.

EXAMPLE 3 (FORMULATION)

Granules were prepared as in Example 2, except using sodium o-aminobenzoate-N-D-glucoside instead of sodium o-aminobenzoate-N-D-xyloside, and the mixture of 96 parts by weight of this granule and 4 parts by weight of calcium stearate was compression-formulated to be tablets 10 mm in diameter.

EXAMPLE 4 (FORMULATION)

94 parts by weight of one of the active ingredients of the present invention (Sodium o-aminobenzoate-N-L-rhamnoside),

6 parts by weight of polyvinyl alcohol and

30 parts by weight of water were mixed and the mixture was processed as in Example 2 to be granules. To 90 parts by weight of the thus processed granules 10 parts by weight of crystalline cellulose were mixed and the mixture was compression-formulated to be tablets 8 mm in diameter. The tablets were coated with syrup, gelatine and precipitated calcium carbonate to be coated tablets.

EXAMPLE 5 (FORMULATION)

0.6 part by weight of one of the active ingredients of the present invention (sodium o-aminobenzoate-N-D-galactoside),

2.4 parts by weight of a non-ionic surfactant and

97 parts by weight of physiological saline solution were mixed under heating and then the mixture was sterilized to be an injection.

EXAMPLE 6 (PRODUCTION OF O-AMINOBENZOIC ACID-N-L-ARABINOSIDE AND ITS SODIUM SALT)

A mixture of 2.3 g of anthranilic acid, 2.5 g of L-arabinose and 0.2 g of ammonium chloride was heated in 30 ml of methanol under a reflux condenser. After the reaction was over, crystals separated out when the reaction mixture was left at room temperature. The crystals thus obtained by filtering were washed with water, methanol and then with ether. The crystals were colorless needles or plates. Yield was 61.3%.

Thus obtained anthranilic acid-N-L-arabinoside was dissolved gradually into an aqueous 1% sodium hydroxide solution containing in total the amount of calculated sodium hydroxide and after filtering, the solution was condensed under reduced pressure. The crystals which separated out by the addition of a large excess of acetone to the condensate was dehydrated and dried. Colorless crystals of sodium salt was obtained at the yield of 100%. The total yield from anthranilic acid was 61.3%.

EXAMPLE 7 (PRODUCTION OF O-AMINOBENZOIC ACID-N-D-XYLOSIDE AND ITS SODIUM SALT)

A mixture of 2.3 g of o-aminobenzoic acid, 2.5 g of D-xylose and 0.2 g of ammonium chloride was heated in 35 ml of ethanol under a reflux condenser. After the reaction was over, the reaction mixture was condensed under reduced pressure to half of the original volume, and after leaving at room temperature crystalline, needles separated out. After washing with water, methanol and then ether, the crystals were recrystallized from ethanol. Colorless needles were obtained at the yield of 74.6%. In the case where ammonium sulfate was used instead of ammonium chloride in the above-mentioned experiment, quite a similar result was obtained.

Thus obtained anthralinic acid-N-D-xyloside was gradually dissolved in an aqueous 1% sodium hydroxide solution containing the alkali in an calculated amount. After filtering and condensing the solution, a large excess of acetone was added to the condensate to obtain wet crystals. Colorless crystals were obtained after dehydration and drying at the yield of 100% based on the anthranilic acid-N-D-xyloside. Total yield from anthranilic acid was 74.6% of theoretical.

EXAMPLE 8 (PRODUCTION OF O-AMINOBENZOIC ACID-N-D-GLUCOSE AND ITS SODIUM SALT)

A mixture of 4.6 g of anthranilic acid, 6.0 g of D-glucose and 0.5 g of ammonium chloride was heated in 40 ml of 95% ethanol under a reflux condenser. After the reaction was over, the reaction mixture was condensed to about one third of the original volume and left in a refrigerator for a night to form of crystals. After collecting crystals by filtration of the reaction solution, and washing the filtered crystals with water, methanol and then ether and further recrystalizing the washed crystals two times from methanol, colorless crystals were obtained at the yield of 4.6%.

By dissolving thus obtained crystals into an aqueous 1% sodium hydroxide solution in stoichiometric proportions, and filtering the solution, the condensing the filtrate and at last adding a large excess of acetone into the condensate, crystals separated out from the acetonic solution. After dehydration and drying, colorless needle-like crystals were obtained at the yield of 100% of the anthranilic acid-N-D-glucoside. Total yield from anthranilic acid was 4.6%.

EXAMPLE 9 (PRODUCTION OF O-AMINOBENZOIC ACID-N-D-GALACTOSIDE AND ITS SODIUM SALT)

A mixture of 2.4 g of anthranilic acid, 3.0 g of D-galactose and 0.2 g of ammonium chloride was heated in 30 ml of 95% ethanol under a reflux condenser. After the reaction was over, the reactant was condensed to one half of the original volume under reduced pressure and left at room temperature to separate crystals. After filtration of the reactant and washing the collected crystals with water, methanol and then ether and further recrystallizing from 95% ethanol, colorless needle-like crystals were obtained at the yield of 16.4%.

Thus obtained crystals of anthranilic acid-N-D-galactoside were dissolved in 1% sodium hydroxide solution in stoichiometric proportions, and after filtration of the solution, and condensation of the filtrate to one half in volume, a large excess of acetone was added to the condensate. Thus separated crystals were dehydrated and dried. Colorless crystals were obtained at the yield of 100% based on the anthranilic acid-N-D-galactoside and at the total yield of 16.4% based on anthranilic acid.

EXAMPLE 10 (PRODUCTION OF O-AMINOBENZOIC ACID-N-L-RHAMNOSIDE AND ITS SODIUM SALT)

A mixture of 2.3 g of anthranilic acid, 2.8 g of L-rhamnose and 0.2 g of ammonium chloride were heated in 25 ml of methanol under a reflux condenser. After the reaction was over, the reactant was left at room temperature to separate crystals. After filtering the reactant and washing the collected crystals with water, methanol and then recrystallizing the washed crystals from 50% methanol, colorless needle-like crystals were obtained at the yield of 9.8%.

Thus obtained anthranilic acid-N-L-rhamnoside was slowly dissolved in 1% sodium hydroxide solution in stoichiometric proportions. After filtering the solution and condensing the filtrate to one half of the original volume, a large excess of acetone was added to the condensate to obtain crystals. By dehydrating and drying the wet crystals, colorless crystals were obtained at the yield of 100% based on the anthranilic acid-N-L-rhamnoside, the total yield based on anthranilic acid being 9.8%.

EXAMPLE 11 (PRODUCTION OF METHYL O-AMINOBENZOATE-N-D-MANNOSIDE)

A mixture of one gram of methyl anthranilate and one gram of D-mannose was heated in 10 ml of ethanol in the presence of 0.1 g of ammonium chloride for about one hour to effect condensation. After the reaction was over, the reactant was left at room temperature to separate crystals. The crystals were recrystallized from 95% ethanol to be colorless crystals with a yield of 60%.

EXAMPLE 12 (PRODUCTION OF O-AMINOBENZOIC ACID-N-D-MANNOSIDE AND ITS SODIUM SALT)

A mixture of 2 g of anthranilic acid, 3 g of D-mannose was heated in 10 ml of ethanol in the presence of 0.2 g of ammonium chloride under a reflux condenser, in a waterbath at 95° to 96° C. After a while, thick crystals separated out. After collecting the crystals by filtration and washing the crystals with water and methanol thoroughly, the crystals were recrystallized from methanol to be colorless needles. The yield was 53.0% based on anthranilic acid.

Thus obtained anthranilic acid-N-D-mannoside was slowly dissolved in 1% sodium hydroxide solution in stoichiometrical proportions. Undissolved matter, if any, was removed by filtration, and the solution (or the filtrate) was condensed under reduced pressure and then a large excess of ethanol was added to the condensate. The crystals separated were collected by filtration and they were dehydrated and dried to give colorless crystals at a yield of 100% based on the anthranilic acid-N-D-mannoside and at the total yield of 53.0% based on anthranilic acid. 

What is claimed is:
 1. A method for the treatment of hypertension, which comprises administering to a mammal suffering from hypertension an effective amount of a compound of the formula: ##STR4## wherein ¹ R denotes one member selected from the group consisting of the residual groups formed by removing OH at 1(alpha) or 1(beta) position from arabinose, xylose, glucose, galactose, rhamnose and mannose, and.sup. R is hydrogen or methyl group, or a pharmaceutically acceptable salt thereof.
 2. The method according to claim 1, wherein said compound is o-aminobenzoic acid-N-L-arabinoside.
 3. The method according to claim 1, wherein said compound is sodium o-aminobenzoate-N-L-arabinoside.
 4. The method according to claim 1, wherein said compound is o-aminobenzoic acid-N-D-xyloside.
 5. The method according to claim 1, wherein said compound is sodium o-aminobenzoate-N-D-xyloside.
 6. The method according to claim 1, wherein said compound is o-aminobenzoic acid-N-D-glucoside.
 7. The method according to claim 1, wherein said compound is sodium o-aminobenzoate-N-D-glucoside.
 8. The method according to claim 1, wherein said compound is o-aminobenzoic acid-N-D-galactoside.
 9. The method according to claim 1, wherein said compound is sodium o-aminobenzoate-N-D-galactoside.
 10. The method according to claim 1, wherein said compound is o-aminobenzoic acid-N-L-rhamnoside.
 11. The method according to claim 1, wherein said compound is sodium o-aminobenzoate-N-L-rhamnoside.
 12. The method according to claim 1, wherein said compound is o-aminobenzoic acid-N-D-mannoside.
 13. The method according to claim 1, wherein said compound is sodium o-aminobenzoate-N-D-mannoside.
 14. The method according to claim 1, wherein said compound is methyl o-aminobenzoate-N-D-mannoside. 